Automatic machine for applying threaded closure caps to collapsible tubes and the like



M y 22, 1962 F. R. MEIERHOFER 3,035,337

AUTOMATIC MACHINE FOR APPLYING THREADED CLOSURE CAPS TO COLLAPSIBLETUBES AND THE LIKE Filed March 12, 1957 3,035,337 AUTOMATIC MAC FORAPPLYENG THREAD- El) CLOSURE CAPS T CGLLAFSKBLE TUBES AND THE LIKEFriedrich Robert Mcierhofcr, Wanlrdorfieldstrasse 105, Bern, SwitzerlandFiled Mar. 12, 1957, Ser. No. 645,58d Claims priority, applicationSwitzerland Mar. 15, W56 8 Claims. (Cl. 29-24tl) The present inventionrelates to an automatic machine for applying threaded closure caps tocollapsible tubes of the type used for dispensing semi-fluid substancessuch as toothpaste, creams and the like and tightening each cap on thethreaded shank of its associated collapsible tube prior to filling thetube.

The automatic machine of the present invention performs the operation ofsecurely screwing a threaded cap on each collapsible tube before thetube is forwarded to the filling machine. At this stage, the large endof each tube is open thereby permitting it to be mounted on a rotarymandrel while the closure cap is applied.

The cap mounting machine comprises a turntable carrying a series ofmandrels. Three stations are provided. At the first, or oiling station,the threaded shank of each tube is daubed with a lubricant. At thesecond station, or cap pickup station, the lubricated shank of the tubeis loosely threaded into a waiting cap held by suitable cap feedingmechanism, but the cap is not tightened. At the third or wrench station,a stationary wrench socket is provided and the loosely threaded cap isinserted in the wrench socket and fully tightened. The maximum torque ofthe final tightening operation is limited by a slip clutch connected topermit rotation of the otherwise stationary wrench socket.

A main power operated camshaft is provided which synchronizes theoperations of the several instrumentalities of the automatic machine andalso causes or controls intermittent angular displacement of theturntable whereby each tube is advanced successively from thelubrieating station to the pickup or threading station and from the cappickup station to the tightening station. The amount of angulardisplacement of the turntable each time that it is advanced is equal tothe angular spacing between adjacent mandrels and the three stations arespaced for simultaneous cooperation with three separate tubes supportedon three different mandrels.

An object of the invention is to avoid breakage of the caps, which areordinarily formed of inexpensive and brittle plastic material, thisbeing effected by the provision of resilient cushioning means and slipclutches so that excessive forces cannot be exerted on the closure capat any time.

Another object of the invention is the provision of interchangeablesocket wrench members for receiving closure caps of different sizes andshapes.

Various additional objects, features and advantages of the inventionwill become apparent upon reading the folllowing specification togetherwith the accompanying drawing forming a part hereof.

Referring to the drawing:

FIGURE 1 is a diagrammatic view of a complete automatic cap applyingmachine shown in side elevation, the machine being partly broken awayand shown in axial section to illustrate details of construction.

FIGURE 2 is an enlarged fragmentary front elevational view showing thelower or terminal end of the cap feeding mechanism.

FIGURE 3 is an enlarged front elevational View of the stationary wrenchsocket.

The machine which is illustratively disclosed comprises a stationarysupporting bracket 1 which carries 3,35,337 Patented May 22, 11962conventional orienting and feeding means for continuously supplyingthreaded closure caps 2. The orienting portion of the cap feeding meansis conventional and is diagrammatically shown as a storage cylinder 3including suitable power operated means for gathering individual caps 2and feeding them With their interiorly threaded end portions alloriented in the same direction. Each cap 2 comprises an interiorlythreaded shank portion 2a which is to be applied to the exteriorlythreaded integrally formed shank portion of a collapsible tube asdescribed below. In conventional manner, the shank portion of eachcollapsible tube has an open-ended axially extending aperture formedtherein. This aperture is not visible in the drawing. The inner end ofthe axial aperture communicates directly with the interior of the tube.The outer end of the aperture is normally closed by the threaded cap.When the cap is removed, the contents of the tube may be dischargedthrough the open-ended axial aperture. The cap 2 also comprises anenlarged octagonal head portion 2b having a slightly rounded crest. Theheads 2b are longitudinally slidably disposed in a cap feeding chute 4with the interiorly threaded cylindrical shank portions 2a of the capsprojecting outwardly between spaced parallel guide members of the chute4-. The chute 4 extends horizontally from the top of the storage andorienting device 3 and thence downwardly, terminating in a verticalportion disposed above a horizontally reciprocable cap holder 7. The capholder 7 is secured to a vertically extending horizontally reciprocablebar 8 by a nut 7a.

Above the nut 7a, the bar 8 is slidably mounted on a guide stud Eta. Atits lower end, the bar is has a boss 9 formed thereon which is fixed tothe right hand end of a horizontally reciprocable slide rod Ill. At itsleft hand end, the slide rod 10 carries axially spaced collars liia and10b. The collars Ma and 10b are engaged by the free end of the upwardlyextending arm of a bellcrank lever 13. The bell-crank lever 13 ispivoted at 13a to a fixed supporting bracket 1312.

A main cam shaft 11, driven at constant speed by a suitable motor orother means (not shown), carries a circular cam 12 which engages a camfollower roller 14 mounted at the free end of the laterally extendingarm of the bell-crank lever 13. When the cam follower roller 14 isengaged by the raised portion 12a of cam 12, the slide rod 10 andvertical bar 3 are displaced toward the left and held in the positionshown in FIG. 1. When the roller 14 engages the depressed portion 12b ofcam 12, suitable springs or other means (not shown) urge the slide rod14) and vertical bar 3 toward the right.

A further cam 15 is fixed to the main camshaft 11 and comprises a raisedportion 15a and a depressed portion 155. A plurality of lever members 16are provided. Each lever member 16 is pivoted intermediate its ends at16:: to a fixed supporting bracket 1611. As shown in the drawing, thelower one or" the levers 16 is provided with a cam follower roller 1'7which engages the cam 15. The corresponding cam follower roller of theupper lever member 16 has been omitted fromthe drawing for simplicity ofillustration. It is to vbe understood, however, that both lever members16 oscillate in unison on their respective pivots lea, suitable meanssuch as a further cam 15 being provided for the actuation of the upperlever member 16.

Thrust bearings 18 are mounted on axially displaceable lower and upperspindles 18a and 1811. Each thrust bearing 13 is pivotally connected tothe upper end of one of the lever members 16 by a pin 19. The machinecomprises a series of leftwardly spring pressed axially movable driverods 21} each provided with a rubber tip 21. Upon movement toward theright of the thrust bearings 18, the spindles 18a and 18b are displacedtoward the right and the axially displaceable drive rods aresimultaneously forced toward the right and placed in driving connectionwith the spindles 18a and 181: by engagement of serrated clutch membersof the clutches 22. The collapsible tubes 23, which are axially slidablymounted on freely rotatable mandrels 24 journaled in ball bearings 24a,are thereupon forced toward the right and are caused to rotate byfrictional engagement with the mandrels 24 and with the rubber tips 21of the drive rods 20, the drive rods 20 being slidably keyed orotherwise connected with the mandreis 24 so that each drive rod 20 andits associated mandrel 24 rotate together as a unit. The resilient tips21 frictionally and yieldingly engage the collapsible tubes 24 at theinner ends of their exteriorly threaded shank portions 23a.

The cap holder 7 comprises a leftwardly spring pressed axiallydisplaceable slide member 25 provided with a leftwardly projecting lowerlip 25a for retaining the lowermost one of the caps 2 within the capfeeding chute 4. The slide member 25 carries a leftwardly projectingrubber bumper 26 positioned for central resilient frictional engagementwith the rounded outer surface or crest of the head of the lowermost cap2 within the cap feeding chute 4. The bumper 26 is eccentrically locatedwith respect to the axis of the slide member 25.

The machine is provided with suitably powered drive gears 27 having widefaced teeth. Only peripheral fragments of the drive gears 27 have beenshown in section in the drawing. The drive gears 27 mesh with pinions 28freely rotatably mounted on the spindles 18a and 18b and connectedthereto for axial displacement therewith. The pinions 28 are connectedto drive their respective spindles 18a and 1811 through friction slipclutches 29 which limit the maximum torque which can be transmitted fromeither of the spindles 18a or 1812 to the rubber tip 21 of any of thedrive rods 20 while the drive rod 20 is connected thereto through thecooperating serrated clutch members of clutches 22.

The mandrels 24, which are eight in number, are carried by a circularturntable 30 which is revoluble about a horizontal axis. The rotationalaxis of the turntable 30 is parallel to and located directly behind theaxis of the upper spindle 18b, as viewed in FIG. 1. The eight mandrels24 are arranged with their axes at the corners of a regular octagonconcentric with the turntable 3%). Suitable mechanism, operated orcontrolled by or in synchronism with the cam shaft 11 causes theturntable 30 to advance periodically through an angle of 22 /2 in acounterclockwise direction as viewed from the right of FIG. 1. Thisadvance of 22 /2 takes place once for each revolution of the cam shaft11. The intermittent periodic rotation of the turntable is produced by aratchet mechanism, a Geneva mechanism, or similar conventional means(not shown) which is operative during a period while both of the camfollower rollers 14 and 17 are in engagement with the depressed portions12b and 15b of cams 12 and 15, respectively. During this period, all ofthe cooperating serrated members of the clutches 22 are disengaged andthe vertical bar 8 is displaced toward the right from the position shownin FIG. 1 so that the turntable carried clutch members of the clutches22 and the tubes 23 may pass freely from station to station.

At the wrench station there is an interchangeable socket wrench member31 which is shown (FIG. 3) having a cap head receiving recess 31a formedtherein. The recess 31a is shaped to receive the enlarged octagonal headof the cap 2 in either of two different angular positions ofpresentation and for this purpose the cap receiving recess 31a isillustratively shown provided with sixteen regularly spaced peripheralindentations for alternate engagement by the eight corners of the caphead 2b. The socket wrench member 31 carries a centrally apertureddiscshaped stop member 32b for limiting inward movement of the cap head2b beyond the cap receiving recess 31a. The socket wrench member 31 issecured by a threaded cap 32 to an axially fixed rotatable spindle 32ajournaled in a ball bearing 32b. Rotation of wrench spindle 32a duringthe cap tightening operation is prevented by a friction type torquelimiting slip clutch comprising a spring pressed rotatable clutch member34a axially slidably splined on the wrench spindle 32a and a fixedfriction facing 34!) in continuous engagement with the rotatable clutchmember 34a. The wrench spindle 32a is hollow and an ejector rod 33 isaxially slidably disposed in the spindle 32a. The ejector rod 33 isprovided with an enlarged head 33a which is yieldingly urged toward theright by a compression spring 33b surrounding the rod 33. The left handend of ejector rod 33 may pass freely through the central aperture inthe stop member 3211 for ejecting the head 2b of a cap 2 from the wrenchrecess 31a after completion of the tightening operation.

The ejection action takes place when the vertical bar 8 moves toward theright upon engagement of the cam follower roller 14 with the depressedportion 12b of cam 12. For this purpose, a lever member 35 pivoted at35a midway between its ends, is mounted on a fixed supporting rod 35band carries rollers 36 and 37 disposed at its ends. A rod 36a is securedto the vertical bar 8 for horizontal movement therewith and forces theroller 36 to the right as the bar 8 is displaced toward the right inresponse to rotation of the cam 12. Thereupon, the head 33a of ejectorrod 33 is pressed leftwardly by the roller 37 and the cap 2 which wapreviously inserted in the socket wrench recess 31a is ejected therefromand the tube 23 upon which the cap has been tightened is forced backleftwardly upon its mandrel 24 so that the tightened cap may move freelypast the wrench station upon the next 22 /2 advance of the turntable 30.

At the cap pickup station, there is cap feed stopping lever 38 (FIGS. 1and 2) which is pivotally connected by a bolt 38a to a depending ear 25bof the spring pressed slide member 25 of the horizontally reciprocatedcap holder 7. At its upper end, the cap feed stopping lever 38 carries aleftwardly projecting rubber friction member 39 for engagement with therounded crest of the cap 2 in the chute 4 which is disposed immediatelyabove the lowermost cap. The cap feed stopping lever 38 is biased torotate in a counterclockwise direction as viewed in FIG, 1 by a tensionspring 40. The feed stopping lever 38 carries a laterally extendingprojection 38]; (FIG. 2) which engages a stationary plate 38c when thecap holder 7 moves leftwardly to the position shown in FIG. 1. Theprojection 38b thus causes clockwise displacement of the stopping lever38 and retraction of its resilient friction member 39 from engagementwith the penultimate cap 2 in the chute 4. When the vertical bar 8 movesto the right after completion of the tightening operation the cap holder'7 likewise moves toward the right and the tension spring 40 rotates thefeed stopping lever 38 in a counterclockwise direction so that itsfriction member 39 presses against the head of the penultimate cap inthe chute 4 and prevents downward gravitational feeding of the capswhile the lower lip 25a is withdrawn from beneath the cap just picked upby the tube at the cap pickup station.

At the lubricating station, there is a hollow cylinder 41 integrallyformed with the vertical bar 8 at its upper end. The cylinder 41 isprovided with a large screw plug 42 threaded into its right hand end andwhich closes the cylinder. The screw plug 42 exerts pressure on a stackof felt discs 43 disposed at the left hand end of the cylinder 41. Theleft hand end of the cylinder 41 is provided with an inwardly turned lip41a for retaining the felt discs 43 in the cylinder 41. Lubricant issupplied to the felt discs 43 by an oil cup 44 provided with a lid 45.

As shown, a conical recess 43a is formed in the stack of discs 43 forreceiving the threaded shank 23a of the tube 23 and daubing lubricantthereon. This daubing may be accomplished in either of two mannersneither one of which is shown in the drawing. One method consists inrelocating the entire cylinder 41 and its contents toward the left asviewed in FIG. 1 so that the shank 23a of the tube will be disposed inthe conical recess 43a and in engagement with the felt discs 43 with thevertical bar 8 in its leftwardly displaced position which is shown inFIG. 1. Then, when the bar 8 moves toward the right after completion ofthe cap pickup and tightening operations at the pickup and wrenchstations, the lubricated shank 23a will be disposed outside the recess43a permitting the shank 23a to move freely onwardly to the cap pickupstation upon the next 22 /2 displacement of the turntable 30.

Alternatively, a spindle similar to the spindles 18a and 18b may beprovided and actuated in unison therewith so that the threaded shank 23ais moved toward the right and into the recess 43a, being rotated thereinto pick up a coating of lubricant. If this is done, however, ejectionmeans similar to the ejection rod 33 at the wrench station and operatingin unison therewith must be provided to eject the lubricated shank 23afrom the recess 43a after the lubricating operation has been completed.

In operation, the cam shaft 11 revolves at constant speed in acounterclockwise direction. Application of lubricant at the lubricatingstation takes place as described above. The turntable has advancedthrough 22 /2 degrees of rotation and a different set of tube 23 ispresented at each station. At the pickup station, a cap 2 with its head2b supported at the bottom of the chute 4 is pressed and frictionallyengaged by the rubber bumper 26 so that it is resiliently held forstarting the thread without breakage. At this stage, the cap is heldslightly against rotation but is sufficiently strongly held to permitthe cap 2 to be threaded loosely on the previously lubricated shank 23awithout being tightened thereon.

At the wrench station, the ejector rod 33 is withdrawn from the wrenchrecess 31a so that a loosely threaded cap may be received therein.

The cam roller 17 next rides up on the raised portion 15a of cam 15 andthe drive rods 24] resiliently press their associated tubes into rotaryengagement with the waiting cap at the pickup station and with thewrench recess 31a at the wrench station. A loosely threaded cap is thuspicked up at the pickup station and the previously loosely threaded capis tightened at the wrench station.

Roller 14 then engages the depressed portion 12b of cam 12. Thereuponthe vertical bar 8 moves to the right. At the pickup station, the capholder 7 moves toward the right and the lower lip 25a of slide member 25is withdrawn from beneath the cap which is then partially or looselythreaded on the shank 23a of the tube. The tube at the pickup stationremains displaced toward the right on its mandrel because the picked upcap is still held in the lower end of the chute 4 (FIG. 2). In thisdisplaced or longitudinally advanced position, however, it will be seenthat the loosely threaded cap will nevertheless clear the socket wrench31 and arrive at the wrench station somewhat spaced away from the wrenchrecess 31a without being pushed back on its mandrel 24. Thislongitudinally advanced position of the tube is indicated in dottedlines at the wrench station in FIG. 1. In the meantime, during movementto the right of the cap holder 7 and before the next rotational step ofthe turntable 30, the friction member 39 of the cap feed stopping lever38 engages the cap immediately above the cap which has just been pickedup.

At the wrench station, movement toward the right of the bar 8 causes thetightened cap to be ejected from the wrench recess 31a. Thereafter, withthe roller 14 still engaging the depressed portion 12b of cam 12, theroller 17 engages the depressed portion 15b of cam 15 so that thebearings 18 and spindles 18a and 1812 move leftwardly and the clutches22 are disengaged. During the period beginning after this time andending before the roller 14 next engages the raised portion 12a of cam12, the turntable 30 is advanced through 22 /2 This movement of theturntable causes the cap which is in the bottom of the chute 4, thenbeing loosely threaded on the shank 23a of the tube by which it has justbeen picked up, to move with the tube downwardly out of the bottom ofthe chute 4 to the wrench station. The cap immediately above the capwhich moves downwardly out of the bottom of the chute 4 is held againstdownward movement by the friction member 39 of the cap feed stoppinglever 38. After completion of the 22 /z movement of the turntable 30 andwhen roller 14 next rides up on the raised portion 12a of cam 12, thebar 8 moves toward the left. The lower lip 25a is then positioned belowthe bottom of the chute 4 and the friction member 39 is thereafterwithdrawn thus permitting downward gravity feed movement of the capswhereby the lowest cap moves downwardly into engagement with theprojecting lower lip 25a of slide member 25 and is thus positioned to bethreaded on the tube located at the pickup station.

While I have shown what I believe to be a preferred embodiment of myinvention, various changes and modifications may be made therein withinthe spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a machine of the type wherein a series of closure caps aresuccessively threaded individually onto cooperating threaded shankportions of open ended collapsible tubes prior to filling said tubes,said tubes being mounted on a series of mandrels carried by turntablemeans and advanced step-by-Step whereby each tube is successivelybrought to and temporarily remains located at each of a plurality ofstations, one of said stations being a cap applying station and anotherstation being a cap tightening station, the improvement which consistsin the provision of a lubricating station to which each tube is broughtprior to being brought to the cap applying station, said lubricatingstation comprising an absorbent lubricant-impregnated packing adaptedfor daubing engagement with the end portion of each shank, meansoperative in synchronism with said turntable means for bringing saidpacking into and out of engagement with each shank while said tuberemains located at said lubricating station between step-by-stepadvancing movements of said turntable, and means for continuouslysupplying lubricant to said packing.

2. The improvement according to claim 1, further comprising frictionalmeans at the cap applying station for lightly threading the cap on thelubricant daubed shank of each tube, said threading means including amember which lightly frictionally engages each cap during relativerotation between the cap and the shank in the course of said lightthreading operation, whereby said cap may slip with respect to saidlast-named member and damage is prevented if a cap fails to threadproperly on a shank.

3. In a machine of the type wherein a series of interiorly threadedclosure caps are successively threaded individually onto cooperatingexternally threaded integrally formed shank portions of open endedcollapsible tubes prior to filling said tubes, each shank portion havingan open-ended axially extending aperture formed therein the inner end ofwhich communicates directly with the interior of the collapsible tube,the outer end of said aperture being adapted for closure by one of saidcaps, said tubes being mounted on a series of mandrels carried byturntable means and advanced step-by-step whereby each tube issuccessively brought to and temporarily remains located at each of aplurality of stations, one of said stations being a cap applying stationand another station being a cap tightening station, the improvementwhich consists in the provision of a rod coaxial with each mandrel andslidably disposed therein, frictional tip means at one end of said rodfor engagement with the inner surface of the tube mounted on saidmandrel at the inner end of said shank portion, means including a clutchmember at the other end of said rod for simultaneously turning said rodand causing axial movement thereof, and means disposed at at least oneof said stations and including a clutch member successively engageablewith the clutch member on each rod for turning said rod in cap threadingdirec- I tion, said last-named means being operative in synchronism withsaid turntable means for causing engagement between said clutch members,said engagement being accompanied by axial displacement of the rod.

4. The improvement according to claim 3, further comprisingtorque-limiting slip-clutch means interposed between said means forturning said rod and said frictional tip means, said torque limitingmeans being effective with said clutch members in driving engagementwith each other to limit the maximum torque which can be applied intightening a closure cap on a tube shank.

5. The improvement according to claim 3, further comprising wrench meansat said tightening station for receiving and holding a partiallythreaded cap stationary therein, said cap being urged into said wrenchmeans by said axial movement of said rod and said frictional tip means.

6. The improvement according to claim 4, further comprising ejectormeans cooperating with said wrench means and connected for operation insymchronism with said turntable means, said ejector means forcing eachcap out of said wrench means in a fully tightened condition accompaniedby corresponding axial movement of said rod.

7. The improvement according to claim 1, wherein said packing is formedas a body having an aperture formed therein for receiving the outer endof the shank portion of a tube therein during the course of said daubingengagement.

8. The improvement according to claim 1, wherein said packing consistsof a stack of felt discs having an outwardly divergent conical recessformed in one end thereof, Said end portion of each shank being receivedin sa d recess during the course of said daubing engagement.

References Cited in the file of this patent UNITED STATES PATENTS1,678,463 Davis July 24, 1928 1,871,799 Koenigshofer Aug. 16, 19322,016,424 Friden Oct. 8, 1935 2,441,642 McDaniel May 18, 1948 2,550,795Flaton May 1, 1951 2,583,457 Woodall Jan. 22, 1952 2,700,443 Boice Jan.25, 1955 2,756,490 Sawdey July 31, 1956 2,762,544 Davis Sept. 11, 1956

